trillion

noun

tril·​lion ˈtri(l)-yən 

1

: a number equal to 1,000 times one billion see Table of Numbers

2

: an indeterminately large number

a trillion mosquitoes out tonight

trillion adjective

trillionth

ˈtri(l)-yən(t)th 

adjective or noun

Examples of trillion in a Sentence

Recent Examples on the Web

For more than a year, starting in 2017, envoys from the United States, Canada, and Mexico met to determine the future of a trade alliance worth trillions of dollars. —Stephania Taladrid, New Yorker, 11 Dec. 2025

But that number is dwarfed by Musk’s ambitious promises at one time that an efficiency commission could measure savings in the trillions. —Bill Barrow, Fortune, 11 Dec. 2025

Every day, as sunlight streams into your eyes, trillions of tiny clocks in your cells reset. —Veronique Greenwood, Time, 9 Dec. 2025

With some analysts forecasting that AI spending will reach into the trillions of dollars by the end of the decade, the boom is boosting excitement about economic advancement and the future of technology while simultaneously raising concerns about privacy, safety and job security. —Ashley Capoot, CNBC, 9 Dec. 2025

Word History

Etymology

French, from tri- + -illion (as in million)

First Known Use

1745, in the meaning defined at sense 2

Rhymes for trillion

• billion
• million
• pillion
• castilian
• civilian
• cotillion
• pavilion
• postilion
• quadrillion
• reptilian
• vermilion
• vermillion

Kids Definition

trillion

noun

tril·​lion ˈtril-yən 

1

: a number equal to 1,000 times one billion see number

2

: a very large number

a trillion mosquitoes out tonight

trillion adjective

trillionth

-yən(t)th 

adjective

trillionth noun